Dual waste valves on my new(er) rig - can I combine them?

Earl E wrote:
...it seemed that many of the more expensive RV's did tie them together...

Late model fiver next to me has three tanks, three valves, one outlet connection. It's a Rear Lounge, so the Mid Kitchen is actually very close to the forward/upper Bedroom and Bathroom. That actually brings the plumbing close together. So Floor Plan might have something to do with the connections. Rear Kitchen could put the tanks or connections a good distance apart.